Comparison of endovascular and surface cooling during unruptured cerebral aneurysm repair

OBJECTIVE: To compare endovascular versus surface methods for the induction and reversal of hypothermia during neurosurgery in a multicenter, prospective, randomized study. METHODS: Patients undergoing elective open craniotomy for repair of an unruptured cerebral aneurysm (n = 153) were randomly assigned (2:1) to undergo whole-body hypothermia to 33°C, either with an endovascular cooling device placed in the inferior vena cava via the femoral vein (n = 92) or with a surface convective air blanket (n = 61). Active rewarming was accomplished using the same devices. RESULTS: Cooling rates in endovascular and surface blanket groups averaged 4.77 and 0.87°C/h, respectively (P < 0.001). When the first temporary arterial or aneurysm clip was placed, 99% of endovascular patients and 20% of surface blanket patients had reached the target of 33°C (P < 0.001). Obese patients were cooled efficiently with the endovascular approach (3.56°C/h). Rewarming rates averaged 1.88°C/h for endovascular patients and 0.69°C/h for surface blanket patients (P < 0.001). By the end of surgery, 89 and 53% of these patients, respectively, had rewarmed to at least 35°C (P < 0.001). On leaving the operating room, 14% of endovascular patients and 28% of surface blanket patients were still intubated (P = 0.035). The overall safety of the two procedures was comparable. No clinically significant catheter-related thrombotic, bleeding, or infectious complications were reported in the endovascular group. CONCLUSION: Endovascular cooling provided superior induction, maintenance, and reversal of hypothermia compared with the surface blanket, without an increase in complications. Endovascular cooling may have clinical benefit for patients undergoing cerebrovascular surgery, as well as patients with acute stroke, head injury, or acute myocardial infarction.